| Author: | Roller, Paul Salmon, | 
|---|---|
| Year: | 1931 | 
| Document Type: | USBM | 
| Issuing Agency: | U.S.Bureau of Mines, | 
| SUDOC: | C 22.5:490 | 
| Series: | Technical paper / United States. Bureau of Mines ; | 
| Report Number: | 490 | 
| Subject: | Microscopy--Technique | 
| Link: | https://hdl.handle.net/2027/mdp.39015077559592 |